Дисертації з теми "Magnetism history"

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1

CALI, ELISA. "Data Analysis and Pattern Recognition in a Magnetometer Experiment." Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1214194.

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The object of our research is the analysis of different series of data that have been collected in an experiment embedded by Prof. Ferruccio Renzoni’s Group in the Laboratory of Coherent Spectroscopy at the Physics Department of University College of London (UCL). The goal of the Thesis has been the determination of a simple, but robust algorithm able to correctly define the contour of an object, as detected by an optical magnetometer, when in presence of noise, as due by the necessary limitations in the technical construction of the experiment. Furthermore, the idea can be applied to a much larger category of experimental situations, not only in this specific kind of measurements or in this restricted field of research. The application of the algorithm gives good results in the determination of the effective size of the studied object.
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2

Whiting, Thomas H. "A study of the lithology and structure of the eastern Arunta Inlier based on aeromagnetic interpretation : a lithological subdivision and structural history of the eastern Arunta Inlier, with particular emphasis on the relationship between magnetic mineral petrogenesis, rock magnetism and aeromagnetic signature /." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phw6125.pdf.

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3

Baias, Maria Antoaneta. "Science and history explored by nuclear magnetic resonance." Aachen Shaker, 2009. http://d-nb.info/99887499X/04.

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4

Morton, David Lindsay Jr. "The History of magnetic recording in the United States, 1888-1978." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/24235.

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5

Coleman, Jessica. "Applying Geoarchaeological Methods on an Iron Age site : Part two of a two-part study discussing Archaeological Prospection for Ytings, Gotland." Thesis, Umeå universitet, Institutionen för idé- och samhällsstudier, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-185792.

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Geoarchaeology has had a long history within archaeology around the world, but not so much so in Gotlandic archaeology. This study is aimed at drawing attention to this by using magnetic susceptibility (MS) and phosphate (P) analysis of an Iron Age site at Ytings, Gotland. This is where a small silver hoard was discovered in 1888, and in 2009 a geophysical survey was done, via metal detector, and concluded with the theory of there being a workshop in the southern field and a farmstead in the north (ArkeoDok, 2011). The first part of this study discussed predictive modeling and whether or not the information available at the time would be enough to generate a reliable model (Coleman, 2016). The first study concluded with not being able to do so since the only discrete data available was from the metal detecting survey, which when used alone is not the most reliable instrument for archaeological prospection (Coleman, 2016). This led to this current study, which is the second part of a two-part study of Ytings. This study is aimed at using geoarchaeological methods for archaeological prospection to illustrate the benefits and need for these types of studies on Gotland, by comparing the MS and P results with the 2015 excavation report.
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6

Baias, Maria Antoaneta [Verfasser]. "Science and history explored by nuclear magnetic resonance / vorgelegt von Maria Antoaneta Baias." Aachen : Shaker, 2009. http://d-nb.info/1002320704/34.

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7

Jones, J. M. "Magnetic minerals and heavy metals in ombrotrophic peat." Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372671.

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8

Clarke, Michèle Louise. "Formation, depositional history and magnetic properties of loessic silt from the Tibetan Front, China." Thesis, University of Leicester, 1992. http://hdl.handle.net/2381/34479.

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9

Dussauge, Isabelle. "Technomedical Visions : Magnetic Resonance Imaging in 1980s Sweden." Doctoral thesis, Stockholm : Filosofi och teknikhistoria, Philosophy and the History of Technology, Kungliga Teknsika högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4671.

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10

Martineau, Ryan J. "Parameterized Least-Squares Attitude History Estimation and Magnetic Field Observations of the Auroral Spatial Structures Probe." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4482.

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Terrestrial auroras are visible-light events caused by charged particles trapped by the Earth's magnetic eld precipitating into the atmosphere along magnetic eld lines near the poles. Auroral events are very dynamic, changing rapidly in time and across large spatial scales. Better knowledge of the low of energy during an aurora will improve understanding of the heating processes in the atmosphere during geomagnetic and solar storms. The Auroral Spatial Structures Probe is a sounding rocket campaign to observe the middle-atmosphere plasma and electromagnetic environment during an auroral event with multipoint simultaneous measurements for fine temporal and spatial resolution. The auroral event in question occurred on January 28, 2015, with liftoff the rocket at 10:41:01 UTC. The goal of this thesis is to produce clear observations of the magnetic eld that may be used to model the current systems of the auroral event. To achieve this, the attitude of ASSP's 7 independent payloads must be estimated, and a new attitude determination method is attempted. The new solution uses nonlinear least-squares parameter estimation with a rigid-body dynamics simulation to determine attitude with an estimated accuracy of a few degrees. Observed magnetic eld perturbations found using the new attitude solution are presented, where structures of the perturbations are consistent with previous observations and electromagnetic theory.
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11

Wilder, Douglas T. "Relative Motion History of the Pacific-Nazca (Farallon) Plates since 30 Million Years Ago." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000069.

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12

Ditty, Melissa Lynn. "FINDING MARS PALEOPOLES FROM MAGNETIZATION EDGE EFFECTS TO DETERMINE THE HISTORY OF MARS’ CORE DYNAMO." UKnowledge, 2015. http://uknowledge.uky.edu/ees_etds/30.

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This is a new method of determining magnetization strength, direction, and paleopole location from magnetic anomalies across edges of the equatorial band of magnetic sources on Mars. Different assumed locations of paleopoles result in different inducing field directions in the vicinity of an edge. Thus, with different paleopoles, the resulting magnetic fields from the edges of magnetic sources are different, and correlate differently with the observed fields. Best correlating observed and computed magnetic edge effect fields yield the potential paleopoles. The total gradient (TG) of the z-component magnetic field was used to identify the edges of magnetization boundaries. Three edge segments yielded meaningful paleopoles. They are: (15°S, 285°E)/(0°, 292.5°E) across the northeast trending edge east of Tharsis; (15°N, 195°E) across the southern boundary located in the Terra Cimmeria and Terra Sirenum area; and (15°S, 165°E)/(45°S, 180°E) across the northeast edge of Hellas Planitia. The effective magnetization in these regions (assuming 40km magnetic layer thickness) is 7.02, 42.13-94.79, and 2.63-3.51 A/m, respectively. Evidence from the overlap of regions of TG and chronostratigraphy suggests that the dynamo was active during the Noachian and may have been active in the early Hesperian.
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13

Jordan, D. W. "Authority, mediation, and response case studies in electrotechnical theory 1880 - 1890." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315221.

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14

Willis, Tracey Anne. "A natural history study in Limb Girdle Muscular Dystrophy 2I : magnetic resonance imaging, spectroscopy and physical outcome measures." Thesis, University of Newcastle upon Tyne, 2012. http://hdl.handle.net/10443/1595.

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Limb Girdle Muscular Dystrophy 2I (LGMD2I) is caused by mutations in the fukutin related protein gene (FKRP). It is an important and frequent cause of LGMD, particularly in Northern Europe, and can range from a severe muscular dystrophy in childhood, very similar to Duchenne muscular dystrophy, to a much milder adult disease. Respiratory involvement and cardiomyopathy are common. This thesis aims to assess the natural history of a particular subset of this rare condition across four main European centres. Thirty eight ambulant LGMD2I patients from Newcastle, London, Paris and Copenhagen were recruited. The age range was 18-64 years and disease duration, 0-49 years. Magnetic resonance imaging (MRI) and Magnetic resonance spectroscopy (MRS) have both been performed. T1-weighted images were used to assess fat infiltration patterns using a qualitative radiological score and a quantitative 3-point Dixon technique, applied over two time points, and was performed to track the progression of fat infiltration. MRI fat infiltration has been correlated with muscle strength and function longitudinally. In the Newcastle upon Tyne cohort, cardiac MRI was also studied assessing the cardiac involvement in this condition. Chapter 1 presents an overview of muscular dystrophy and the current knowledge in LGMD2I and chapter 2 includes a literature review of both skeletal muscle and cardiac imaging. Chapter 3 focuses on the methodology of the study, including the patient demographics, physical assessment tools and MRI and MRS specifics. Chapters 4 -9 contain the results section; including physical and functional assessments, both cross-sectional and longitudinal, the cross sectional and longitudinal MRI results, skeletal MRS, cardiac MRI data and the FKRP registry respectively. Discussion of the results is found at the end of each chapter. Chapter 10 concludes with areas for future research.
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15

Hendricks, Hays Birkhead. "Louisville's Lustrons : houses with magnetic appeal." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/897512.

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The housing shortage in the United States at the close of World War II led President Truman and his National Housing Expediter, Wilson W. Wyatt, Sr., to enact the Veteran's Emergency Housing Act. Enacted in the spring of 1946, one goal of the V.E.H.A. was to encourage the production of prefabricated and factory-built housing units.The Lustron Homes Corporation, founded by Carl Strandlund, was a subsidiary of Chicago Vitreous Enamel Products Company which received over $37 million from the Federal Government between 19461950, in order to manufacture standardized all-steel houses.This creative project explores the wartime and postwar housing situation across the country, and specifically, in Louisville, Kentucky. An interview with Wilson W. Wyatt, Sr. is included.The production, assembly, and sales practices of the Lustron Homes Corporation are explored through research, and through an interview with the regional salesman who represented Kentucky. Documentation and photographs of Louisville's Lustrons are included.
Department of Architecture
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16

Smith, Dominic. "Magnetics and Electromagnetics on Monks Mound at the Cahokia Mounds State Historic Site near St. Louis, Missouri." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1674100591&sid=3&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Анотація:
Thesis (M.S.)--Southern Illinois University Carbondale, 2008.
"Department of Geology." Keywords: Cahokia Mounds, Electromagnetics, Magnetics, Monks Mound. Includes bibliographical references (p. 143-148). Also available online.
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17

Cerf, Corinne. "Structure of the globular domain of histone H1 determined by nuclear magnetic resonance." Doctoral thesis, Universite Libre de Bruxelles, 1994. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212678.

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18

LUZZAGO, STEFANO. "REPEATED MRI SCANS DURING ACTIVE SURVEILLANCE FOR PROSTATE CANCER: NATURAL HISTORY OF PROSTATIC LESIONS AND UPGRADING RATES OVER TIME." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/881234.

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Objectives To test upgrading rates in patients on Active Surveillance (AS) for prostate cancer (PCa) after serial multiparametric magnetic resonance imaging (mpMRI) scans. Materials and methods Retrospective analysis of 558 patients. Five different criteria of mpMRI progression were used: 1) PI-RADS score increase; 2) lesion size increase; 3) EPE score increase; 4) overall mpMRI progression; 5) number of criteria for mpMRI progression (0 vs. 1 vs. 2-3). Moreover, two definitions of PCa upgrading were evaluated:1) ISUP GG≥2 with >10% of pattern 4; 2) ISUP GG≥3. The estimated annual percent changes (EAPC) methodology depicted temporal trends of mpMRI progression criteria. Sensitivity, specificity, positive predictive (PPV) and negative predictive value (NPV) of mpMRI progression criteria were analysed. Multivariable logistic regression models tested PCa upgrading rates. Results Lower rates over time of all mpMRI progression criteria were observed. The NPV of serial mpMRIs spans from 90.5 to 93.5% (ISUP GG≥2 with >10% of pattern 4 PCa upgrading) and from 98 to 99% (ISUP GG≥3 PCa upgrading), according to the different mpMRI progression criteria. A PSA-D cut-off of 0.15 ng/ml/ml sub stratified those patients who could skip a prostate biopsy. In multivariable logistic regression models testing PCa upgrading rates, all five mentioned mpMRI progression criteria achieved independent predictor status. Conclusions: During AS, approximately 27% of patients experience mpMRI progression at first repeated scan. However, the rates of mpMRI progression decrease over time at subsequent mpMRIs. Patients with stable mpMRI findings and with PSA-D<0.15 ng/ml/ml could safely skip surveillance biopsies. Conversely, patients who experience mpMRI progression should undergo a prostate biopsy.
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19

Sullivan, Nicholas B. "Refinements to the Depositional History of Lower Silurian Strata in the Northeastern United States by means of Conodont Biostratigraphy, d13C Chemostratigraphy, Sequence Stratigraphy, and Magnetic Susceptibility." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112630.

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20

Spurgeon, V. Leanne. "Sedimentology of historic and prehistoric deposits in the drainage basin of Deep River and Muddy Creek on the Piedmont of North Carolina." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1268.

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Анотація:
Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains viii, 152 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 62-64).
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21

Di, Chiara Anita <1983&gt. "Paleosecular variation of the magnetic field recorded in Pleistocene-holocene volcanics from Pantelleria (italy) and Azores archipelago (portugal): implications for local volcanic history." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5177/1/DI_CHIARA_ANITA_TESI.pdf.

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The primary goal of volcanological studies is to reconstruct the eruptive history of active volcanoes, by correlating and dating volcanic deposits, in order to depict a future scenario and determine the volcanic hazard of an area. However, alternative methods are necessary where the lack of outcrops, the deposit variability and discontinuity make the correlation difficult, and suitable materials for an accurate dating lack. In this thesis, paleomagnetism (a branch of Geophysics studying the remanent magnetization preserved in rocks) is used as a correlating and dating tool. The correlation is based on the assumption that coeval rocks record similar paleomagnetic directions; the dating relies upon the comparison between paleomagnetic directions recorded by rocks with the expected values from references Paleo-Secular Variation curves (PSV, the variation of the geomagnetic field along time). I first used paleomagnetism to refine the knowledge of the pre – 50 ka geologic history of the Pantelleria island (Strait of Sicily, Italy), by correlating five ignimbrites and two breccias deposits emplaced during that period. Since the use of the paleomagnetic dating is limited by the availability of PSV curves for the studied area, I firstly recovered both paleomagnetic directions and intensities (using a modified Thellier method) from radiocarbon dated lava flows in São Miguel (Azores Islands, Portugal), reconstructing the first PSV reference curve for the Atlantic Ocean for the last 3 ka. Afterwards, I applied paleomagnetism to unravel the chronology and characteristics of Holocene volcanic activity at Faial (Azores) where geochronological age constraints lack. I correlated scoria cones and lava flows yielded by the same eruption on the Capelo Peninsula and dated eruptive events (by comparing paleomagnetic directions with PSV from France and United Kingdom), finding that the volcanics exposed at the Capelo Peninsula are younger than previously believed, and entirely comprised in the last 4 ka.
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22

Di, Chiara Anita <1983&gt. "Paleosecular variation of the magnetic field recorded in Pleistocene-holocene volcanics from Pantelleria (italy) and Azores archipelago (portugal): implications for local volcanic history." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5177/.

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Анотація:
The primary goal of volcanological studies is to reconstruct the eruptive history of active volcanoes, by correlating and dating volcanic deposits, in order to depict a future scenario and determine the volcanic hazard of an area. However, alternative methods are necessary where the lack of outcrops, the deposit variability and discontinuity make the correlation difficult, and suitable materials for an accurate dating lack. In this thesis, paleomagnetism (a branch of Geophysics studying the remanent magnetization preserved in rocks) is used as a correlating and dating tool. The correlation is based on the assumption that coeval rocks record similar paleomagnetic directions; the dating relies upon the comparison between paleomagnetic directions recorded by rocks with the expected values from references Paleo-Secular Variation curves (PSV, the variation of the geomagnetic field along time). I first used paleomagnetism to refine the knowledge of the pre – 50 ka geologic history of the Pantelleria island (Strait of Sicily, Italy), by correlating five ignimbrites and two breccias deposits emplaced during that period. Since the use of the paleomagnetic dating is limited by the availability of PSV curves for the studied area, I firstly recovered both paleomagnetic directions and intensities (using a modified Thellier method) from radiocarbon dated lava flows in São Miguel (Azores Islands, Portugal), reconstructing the first PSV reference curve for the Atlantic Ocean for the last 3 ka. Afterwards, I applied paleomagnetism to unravel the chronology and characteristics of Holocene volcanic activity at Faial (Azores) where geochronological age constraints lack. I correlated scoria cones and lava flows yielded by the same eruption on the Capelo Peninsula and dated eruptive events (by comparing paleomagnetic directions with PSV from France and United Kingdom), finding that the volcanics exposed at the Capelo Peninsula are younger than previously believed, and entirely comprised in the last 4 ka.
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23

Boland, Paul William. "Morphometric analysis of data inherent in examination by magnetic resonance imaging : importance to natural history, prognosis and disease staging of squamous carcinoma of the oral cavity." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:934e1e5a-24db-40ab-ab54-5e58901a9c2a.

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Magnetic resonance imaging plays an important yet underutilized role in determining the natural history and prognosis of oral carcinoma. Depth of tumour invasion is an emergent factor in the oral cancer literature. However, problems exist with the definition of cut-points suitable for inclusion in TNM staging criteria. Statistical methodology represents a possible explanation but is underexplored. In this work, a review of the depth of invasion literature is conducted with emphasis on statistical technique. As well, statistical simulation is used to explore the implications of the of the minimum p-value method. The results demonstrate that the use of continuous variable categorization and multiple testing is widespread, and contributes to cut-point variability and false-positive tests. Depth, as a predictor of OCLNM and survival, must be questioned. The volume of tumour invasion is a promising prognostic factor that has not been fully investigated in the oral carcinoma literature. In this work, the volume of tumour invasion is measured on MRI and compared to thickness and maximum diameter in its capacity to predict 2-year all-cause, disease-related and disease-free survival, as well as occult cervical lymph node metastasis prediction. As part of a comprehensive approach, morphometric factors are incorporated into multifactor predictive models using regression, artificial neural networks and recursive partitioning. It is evident that MRI-based volume is superior all other linear measurements for both occult cervical lymph node metastasis and survival prediction. Artificial neural networks wee superior to all other techniques for survival prediction. There is a case for a unified artificial neural networks model for survival prediction that uses volume, midline invasion and N-stage to determine prognosis. This model can be used to determine individualized probabilities of 2-year survival. The lateral extrinsic muscles of the tongue lie just beneath the surface of the lateral tongue, yet their invasion is a criterion for T4 classification using the TNM staging system. In this work, the Visible Human Female is used to conduct an anatomic study of the extrinsic muscles of the tongue. Linear measurement is used to quantify the distance from the surface mucosa to the most superficial muscle fibres of the styloglossus and genioglossus. Further, the lateral extrinsic muscles are poorly demonstrated on MRI. An anatomic atlas of the tongue is fused with MRI images of oral carcinoma to demonstrate lateral muscle invasion. The results demonstrate that the styloglossus and hyoglossus lie very close to the surface of the lateral tongue, in some cases passing within 1 mm of the surface mucosa. These extrinsic muscles are readily invaded by even small tumours of the lateral tongue. Strict application of the TNM T4a criteria leads to unnecessary upstaging as these carcinomas do not warrant the prognosis and aggressive treatment of Stage IV disease. Extrinsic muscle invasion should be removed as a T4a criterion for the oral cavity. A separate category, T4a (oral tongue) specifying invasion of the genioglossus is also recommended. This work presented in this thesis is an original contribution to the field of oral cavity cancer research and has determined that there is capacity for improvement in current efforts to determine the natural history and prognosis of oral cavity squamous cell carcinoma. This thesis is the first to examine the role of statistical methodology in oral carcinoma depth of invasion cut-point variability. Further, this work presents an original approach to the prediction of regional metastasis and survival using advanced multivariate modeling techniques. No other work explored MRI-measured volume using the substantial sample size gathered in this thesis. Finally, this work is the first to demonstrate that lateral extrinsic muscle invasion is an unnecessary component of the T4a (oral cavity) classification criteria and should be reconsidered.
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24

Raúl, Sitoe Sandra. "Environmental history in southern Mozambique : Reconstruction of flooding events, hydroclimate and sea-level dynamics since mid-Holocene." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148465.

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Анотація:
The aim of this thesis has been to reconstruct paleoenvironment, paleohydrology and paleoclimate in coastal southern Mozambique, with emphasis on tracing past flooding events on the lower Limpopo River floodplain. In order to extend flood chronologies beyond periods covered by instrumental data, sediments from lakes on the floodplain were studied (Lake Lungué, Coassane Oxbow, Lake Magandane and Lake Soane). Past sea-level variations and climate changes were deduced by analyzing sediments from coastal sites north of the floodplain area (Lake Chilau, Lake Nhauhache and Macassa Bay). To achieve the established objectives, a multi-proxy approach was applied on most of the retrieved sediment cores, involving analysis of mineral magnetic parameters, grain-size and organic carbon in combination with analysis of microfossils such as diatoms and/or phytoliths. Chronologies for the constructed time-series analysis were obtained by radiocarbon dating and age-depth modelling. The synthesized data from the sampled sites on the Limpopo River floodplain suggest that the area was affected by at least 16 flooding events of variable magnitudes during the studied period. These are dated to c. AD 940, 980, 1040, 1100, 1250, 1300, 1370, 1580, 1665, 1730, 1755, 1855, 1920, 1945, 1970 and 2000. In calibrated years BP these ages correspond to 1010, 970, 910, 850, 700, 650, 580, 370, 285, 220, 195, 95, 30, and 5 cal yrs BP. The two youngest are dated to 20 and 50 years AP (After Present being 1950). Proxy data further suggest that southern Africa was subject to two periods of sea-level highstands, at c. 5000–4200 BC (6950–6150 cal yrs BP) and AD 300–950 (1650–1000 cal yrs BP). The former represents the middle part of the postglacial climatic optimum. The wettest period in the Limpopo River floodplain was reported between AD 1360 and 1560 (590 and 390 cal yrs BP) in the Lake Lungué record, while Lake Chilau experienced wet conditions between AD 1200 and 1400 (750 and 550 cal yrs BP), then returning to drier conditions that prevailed until c. AD 1600. In Lake Nhauhache, however, drier conditions prevailed from c. AD 1200–1700 (750–250 cal yrs BP), shifting towards wetter at c. AD 1900 (50 cal yrs BP). The deviating signals between records can partly be explained by Lake Lungué basin being located on the Limpopo River floodplain, responding to flooding events associated with precipitation upstream the drainage area. Therefore, wet and dry periods in floodplain lakes (e.g. Lake Lungué) are not expected to correlate with precipitation changes on a local scale, as indicated by e.g. Lake Nhauhache. This is supported by a relatively weak agreement between Lake Lungué record and other nearby records (outside the floodplain), but a better correlation with records from the upper catchment, where a more regional climate signal is provided of the southern African summer rainfall region.
Denna avhandling behandlar studier av paleomiljöer i södra Mozambique med fokus på översvämningshistorik i Limpopo-flodens nedre lopp. Tidsspannet är mitt- och sen-holocen och inkluderar även klimat och havsnivåvariationer. Följande analysmetoder har applicerats på ett flertal sedimentkärnor för att belysa ovanstående frågeställningar: mineralmagnetiska parameterar, kornstorlek, organiskt kol samt kiselmikrofossil (diatoméeter och fytoliter). Åldrar har bestämts med 14C-metoden.  Analyserna visar att mineralmagnetiska parametrar är lämpliga för att identifiera översvämningar, speciellt magnetisk susceptibilitet och SIRM. Dessa parametrar visar på ett sediments magnetiska kornstorlerkar och koncentrationen av finkorniga magnetiska mineral. Även kornstorleksanalyser fungerade som ett bra komplement till dessa metoder. Sammantaget har ett minimum av 16 översvämningar registrerats i Limpopo/flodens nedre lopp under de senaste 1100 åren. Särskilt stora översvämningar har daterats till AD 1250 (700 kal år BP), AD 1370 (580 kal år BP), AD 1580 (370 kal år BP), AD 1855 (95 kal år BP), AD 1920 (30 kal år BP), AD 1970 (20 kal år AP) och AD 2000 (50 kal år AP), där AP betyder ”after present”, vilket är 1950. Mindre kraftiga översvämningar har daterats till AD 940 (1010 kal år BP), AD 980 (970 kal år BP), AD 1040 (910 kal år BP), AD 1100 (850 kal år BP), AD 1300 (650 kal år BP), AD 1665 (285 kal år BP), AD 1730 (220 kal år BP), AD 1755 (195 kal år BP) och AD 1945 (5 kal år BP). Skriftliga källor visar på att åtminstone åtta översvämningar har ägt rum under de senaste 62 åren. Under samma period har denna undersökning registrerat två händelser, vilket indikerar att endast ett fåtal har registrerats med ovan nämnda metoder. Det är sannolikt att sedimentationsmönstret under en översvämning är komplicerat och inte heller likartad från gång till gång. Detta innebär att ett flertal sedimentkärnor behöver analyseras och dateras väl. Ytterligare en försvårande faktor är flodens mycket aktiva meandringsaktivitet. Analys av diatoméer har visats vara värdefulla när det gäller översvämningshistorik, klimatförändringar och havsytevariationer. Sedimenten i den något till flodslättens nedre lopp perifert belägna sjön Lungué indikerar fuktiga förhållanden mellan AD 1360 och 1560 (590 till 390 kal år BP). Kombinerade fytolit- och diatoméanalyser av sedimenten i sjön Chilau indikerar fuktiga förhållanden från AD 1200 till 1400 (750 till 550 kal år BP), varefter torrare förhållanden rådde till ca AD 1600 (350 kal år BP). Diatoméanalys av sedimenten i sjön Nhauhache indikerar generellt sett torrare förhållanden mellan AD 1200 och AD 1700 (750 till 250 kal år BP) då klimatet blev fuktigare. De fuktiga och torra förhållanden som dokumenterats i sjön Lungué och översvämningshistoriken korrelerar inte helt med lokala nederbördsförhållanden. Däremot stämmer erhållna data bättre med förhållanden i den övre delen av Limpopoflodens dräneringsområde. Även sjöar och fyllda meanderbågar på själva flodslätten verkar reagera tydligare på översvämningar orsakade av nederbörd i den övre delen av flodloppet. Undersökningen indikerar två faser av en förhöjd havsyta längs kusten i södra Mozambique. En äldre fas är daterad till ca 5000–4200 f.Kr. (6950–6150 kal år BP), vilken representerar den mellersta delen av det postglaciala värmeoptimet. Denna tolkning stöds även av andra undersökningar. En yngre fas har daterats till AD 300–950 (1650–1000 kal år BP), vilken korresponderar till en period med något förhöjda temperaturer i ett globalt perspektiv.
O presente projecto teve como objectivo a reconstrução do paleoambiente, paleohidrologia e paleoclima da costa Sul de Moçambique, com ênfase na identificação de vestígios de eventos de cheias que tenham, no passado, afectado a planície de inundação do Rio Limpopo, com vista a fazer a extensão das datações de cheias para o período anterior aos instrumentos de medição. Deste modo, foram estudados sedimentos recuperados através de testemunhos de sondagem em lagos dentro da planície de inundação (Lago Magandane, Lago Lungué, Lago Soane e o canal abandonado Coassane). As variações do nível do mar e mudanças climáticas do passado foram deduzidas a partir da análise de sedimentos de áreas costeiras a norte da planície de inundação (Lago Chilau, Lago Nhauhache e a Baía de Macassa). Para o alcance destes objectivos, os sedimentos dos testemunhos de sondagem recuperados foram submetidos a várias análises laboratoriais que incluem propriedades de minerais magnéticos, granulometria, teor de matéria orgânica e de microfósseis (diatomáceas e fitólitos). Para o estabelecimento do modelo cronológico foram usadas datações pelo método 14C feitas em matéria orgânica, assim como conchas de gastrópodes e bivalves. A combinação dos resultados obtidos para os pontos de amostragem localizados dentro da planície de inundação do Rio Limpopo, sugerem que esta área foi afectada por um mínimo de 16 eventos de cheias de variada magnitude nos últimos 1100 anos. As cheias de alta magnitude tiveram lugar nos anos 1250, 1370, 1580, 1855, 1920, 1970 e 2000. Por seu turno, as cheias de magnitude moderada ocorrerram nos anos 940, 980, 1040, 1100, 1300, 1665, 1730, 1755 e 1945.. Os anos a negrito são indicativos de eventos de cheias de alta magnitude. O número total de eventos identificados no presente estudo é um mínimo que poderá ter afectado a planície de inundação, tendo em consideração que fontes escritas reportam a ocorrência de pelo menos oito eventos nos últimos 62 anos, tendo o presente estudo revelado somente dois. Isto indica que apenas eventos de cheias intensos podem ser revelados pelos métodos aplicados nesta investigação. Adicionalmente, este estudo mostra a necessidade de aumentar o número de pontos de amostragem para permitir a identificação de mais eventos de cheias ocorridos no passado, devido à diferenciada resposta sedimentológica e geomagnética às cheias, a qual se encontra directamente relacionada à distância do rio meandrante. As análises de microfósseis de diatomáceas permitiram reconstruir o paleoclima e as influências do nível do mar nas áreas de estudo deste projecto. Os registros de diatomáceas do Lago Lungué indicam um período húmido entre AD 1360 e 1560. No Lago Chilau, dados de diatomáceas e fitólitos sugerem condições de humidade entre AD 1200 e 1400. Por seu turno, no Lago Nhauhache, condições de seca dominam entre AD 1200 e 1700. As condições de seca e humidade documentadas no Lago Lungué e os eventos de cheias revelados pelos sedimentos analisados da planície de inundação do Rio Limpopo não mostram total correlação com períodos de baixa e alta precipitação a nível local, mas apresentam boa correlação com evidências a montante na área de drenagem do Rio Limpopo. Em geral, lagos activos ou preenchidos por sedimentos mostrarão ser mais susceptíveis a cheias com origem a montante do que a nível local. As investigações conduzidas permitiram identificar dois períodos de alto nível do mar na região sul de Moçambique. A fase mais antiga teve lugar há cerca de 5000–4200 BC (6950–6150 anos do calendário BP), representando a fase mais recente do pós-glaciar climático óptimo (postglacial climatic optimum, PCA). A fase recente é datada de AD 300–950 (1650–1000 anos do calendário BP), correspondendo a um período de temperaturas relativamente altas a nível global.
Climate and Environmental Research
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25

Farwig, Victoria Jane. "Evaluation of mineral magnetic properties and thermal activation characteristics of soil material in reconstructing post-fire sediment redistribution and fire history, Sydney Basin, Australia." Thesis, Swansea University, 2006. https://cronfa.swan.ac.uk/Record/cronfa43195.

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26

Magalhães, Antônio de Pádua. "Matéria Elétrica e Forma Magnética: Experimentos e concepções de William Gilbert no De Magnete." Pontifícia Universidade Católica de São Paulo, 2007. https://tede2.pucsp.br/handle/handle/13358.

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Анотація:
Made available in DSpace on 2016-04-28T14:16:28Z (GMT). No. of bitstreams: 1 Antonio P Magalhaes.pdf: 3251730 bytes, checksum: 0e3e5794c6a8e24e374f425ce2d5079e (MD5) Previous issue date: 2007-03-15
William Gilbert of Colchester (1544-1603), one of the many personal physicians of Queen Elizabeth the First, was a prominent figure regarding the studies of electric and magnetic phenomena between the end of the XVI century and the beginning of the XVII century. In his attempt to reformulate the approach given to knowledge about the nature of these phenomena in his days, as well as the appropriate way to elaborate such process, William Gilbert would then develop various original and influent works, which would be published in the year of 1600 in his book De Magnete. His declared purpose would be to establish a new philosophy based on arguments and true observations, demonstrated by experiments and experiences. Consequently, he would then create new concepts and conceptions about the nature of electric and magnetic matter. The present work aims to go further in the analysis of this specific book, undertaking initially some aspects of its structure, editions and repercussions, as well as the rare biographical data on the author. Next, we investigate the relationship between De Magnete and some of the sources suggested by the author. Particularly those concerning the experiments regarding the magnetic phenomenon, specially the Epistola attributed to the medieval thinker Petrus Peregrinus, The New attractive (1581), written by the navigation craftsman Robert Norman. We also take into consideration, William Gilbert s criticism of book VII of Magia Naturalis (1558) written by the renaissance magician, Giambattista della Porta. We finally deal with the conceptions of electric matter and magnetic form proposed by William Gilbert. The study of the attractions would force him to separate electric bodies, imperfect for acting through matter, from magnetic bodies, perfect for acting through form. Therefore, form should present similarity with a superior soul and a resemblance with the skies
William Gilbert de Colchester (1544-1603), um dos muitos médicos pessoais da Rainha Elizabeth I, foi uma das mais destacadas figuras no que diz respeito aos estudos sobre os fenômenos elétrico e magnético entre o final do século XVI e início do século XVII. Em sua tentativa de reformular a abordagem dada ao conhecimento sobre a natureza desses fenômenos, em seus dias, bem como a própria maneira de elaborá-lo, William Gilbert desenvolveria trabalhos em muitos pontos originais e influentes, que seriam publicados, no ano de 1600, em seu livro De Magnete. Seu objetivo declarado seria estabelecer uma nova Filosofia baseada em argumentos e observações verdadeiros, demonstrados por experimentos e experiências. Assim, ele criaria novos conceitos e concepções sobre a natureza da matéria elétrica e magnética. O presente trabalho propõe-se a aprofundar a análise dessa obra, retomando inicialmente alguns aspectos de sua estruturação, edições e repercussões, bem como os raros dados biográficos de seu autor. Em seguida, busca-se investigar relações dessa obra com algumas das fontes sugeridas pelo autor, particularmente aquelas concernentes a experimentos relacionados ao fenômeno magnético, em especial a Epistola atribuída ao pensado medieval Petrus Peregrinus, o The New attractiue (1581), escrito pelo artesão náutico Robert Norman e também as críticas que William Gilbert desferiu contra o livro VII do Magia Naturalis (1558) escrito pelo mago renascentista, Giambattista della Porta. Por fim abordam-se as concepções de matéria elétrica e forma magnética propostas por William Gilbert. O estudo das atrações exigia-lhe separar os corpos elétricos, imperfeitos por atuarem através da matéria, dos corpos magnéticos, perfeitos por atuarem através da forma. Dessa maneira, a forma deveria apresentar similaridade com uma alma superior, à semelhança dos céus
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27

Roberts, Jody Alan. "Instruments and Domains of Knowledge: The Case of Nuclear Magnetic Resonance Spectroscopy, 1956-1969." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/42766.

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In this thesis, I traced the development of Nuclear Magnetic Resonance (NMR) Spectroscopy through the pages of the Journal of Organic Chemistry (JOC) from the year 1956 to 1969 to understand how organic chemists and Varian Associates?the makers of the first commercial NMR spectrometers?negotiated the identity of the NMR spectrometer. The work of the organic chemists was examined through their publications in the JOC. Examining the abstracts from the JOC between the years 1956 and 1969 developed an understanding of the ways in which organic chemists used the instrument. To understand the role Varian Associates played in the development of NMR, I examined the company?s advertisements in the JOC. I traced the changes in advertising style and format in order to see how Varian Associates expected their instruments to be used. I drew three conclusions from this work: 1) organic chemists and Varian Associates together determined what an NMR spectrometer was and how it could be used; 2) the identity of the instrument was negotiated by these two groups, and the novel use of the instrument by the organic chemists and new schemes in advertising on the part of Varian Associates were attempts to shift this identity; 3) NMR spectroscopy was a domain of knowledge that was embodied in the NMR spectrometer, and that could only be accessed through the instrument.
Master of Science
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28

Yeh, Ping-Hong. "Traumatic osteochondrosis of the third metacarpal bone condyle in thoroughbred racehorses : gross, histological, high detail radiographic, microradiographic and magnetic resonance imaging findings and their relationships with exercise history /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.

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29

Simon, Marek. "Chromatin Modified! Dynamics, Mechanics, Structure, and HIV Integration." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1336752099.

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30

Bolteau, Blandine. "La magnétisante histoire de la goutte fakir ou étude des propriétés de mouillage de surfaces superhydrophobes à géométrie magnétiquement modulable." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS062/document.

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Dans cette thèse, nous avons travaillé sur la mise au point de surfaces superhydrophobes modèles dont la mouillabilité peut être contrôlée par un stimulus externe. Composées de forêts de piliers micrométriques élastomères à forts rapports d'aspect dans lesquels sont incorporées des particules magnétiques, les surfaces présentent, via l'application d'un champ magnétique externe, une orientation modulable des piliers, donc une rugosité de surface adaptable. En faisant varier la géométrie, l'élasticité et l'aimantation de ces derniers, nous avons pu mettre en évidence les points suivants. Nous avons vu dans un premier temps qu’en accord avec la littérature, et en l’absence de champ magnétique, l’hystérèse de mouillage augmente avec la fraction de surface. Cependant, elle reste constante lorsque l’élasticité des piliers varie. Résultat déroutant, car à l’échelle du pilier, il existe bel et bien une différence de mobilité des piliers entre les piliers les plus rigides et les plus complaisants qui subissent la traction de la ligne triple.Nous avons ensuite montré que l’orientation des piliers changeait significativement l’angle de glissement via l’application d’un champ magnétique. De plus, le glissement de la goutte sur la surface est favorisé lorsque les piliers sont orientés à l’opposé de la pente. Enfin, nous avons pu contrôler la façon dont une goutte d’eau se déplace sur une surface inclinée en deçà de l’angle de glissement, puisqu’elle n’avance vers le bas de la surface que si une actuation magnétique est appliquée. Ces surfaces seront une source d’étude intéressante pour comprendre comment moduler le mouillage ou l’écoulement de liquide en état fakir
During this thesis, we have developped superhydrophobic surfaces whose wettability can be controlled by an external magnetic stimulus. Formulating a network of elastomeric and magnetic micro-pillars with high aspect ratio allows the orientation of the pillars through magnetic forces, hence an adaptable surface roughness. Moreover, modulating the geometry, elasticity and magnetization of pillars allowed us to highlight the following conclusions.We have seen first that in agreement with the literature, without magnetic field, the wetting hysteresis increased with the surface fraction. However, it remains constant varying the elasticity of pillars. This conclusion is confusing, because at the pillar scale, there is indeed a difference of mobility between rigid and flexible pillars due to the force exerted by the triple line.We then demonstrated that the deflexion of the pillars can change significantly the sliding angle due to the applied magnetic field. Moreover, sliding of the droplet on such a surface is promoted when pillars are deflected against the slope.Finally, we managed to control the displacement of a droplet on a surface which is tilted with an angle below the sliding angle : it moves forward from the surface only if magnetic actuation is applied. This surfaces will be an attractive source of study in order to understand how to modulate wetting and liquid flow in fakir state
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31

Mitchell, Stephanie Bianca. "Sediment Dispersal Processes and Anthropogenic Impacts at Rex Lake, Summit County, Ohio." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1442416877.

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32

Pflug, Norbert. "Der historische Eisenerzbergbau im Osterzgebirge und Elbtalschiefergebirge – eine geographisch-geologische Landschaftsanalyse." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-126893.

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Im Osterzgebirge sowie im nordöstlich daran angrenzenden Elbtalschiefergebirge wurde mit Unterbrechungen über mehrere Jahrhunderte Bergbau auf Eisen betrieben. Für die Besiedlung, den Bergbau auf andere Metalle, die Landwirtschaft und das Handwerk in der Region hatte der Eisenerzbergbau eine gewisse Bedeutung. Im Gegensatz zum Silber- und Buntmetallbergbau ist über den Eisenerzbergbau allerdings nur relativ wenig bekannt. Das Ziel dieser Diplomarbeit bestand deshalb darin, eine zusammenfassende geologisch-geographische Darstellung, die sowohl den historischen Eisenerzbergbau im Osterzgebirge als auch den historischen Eisenerzbergbau im Elbtalschiefergebirge beinhaltet, zu erarbeiten. Um ein hohes Maß an Vollständigkeit zu gewährleisten, wurden die Erkenntnisse aus Archiven, Bibliotheken und Sammlungen zusammengetragen. Überdies wurde auch auf das Fachwissen von Heimatvereinen, Bergbaumuseen und Hobbyhistorikern zurückgegriffen. Ferner wird im Rahmen dieser Arbeit untersucht, welche Typen von Eisenerzlagerstätten es im Osterzgebirge und im Elbtalschiefergebirge gab, wie diese entstanden sind, um welche Mineralisation und um welche Art von Eisenerztypen es sich dabei handelt. Mit den gegenwärtig zur Verfügung stehenden Methoden der Analytik (REM-EDX) werden zudem die Mineralparagenese und die chemische Zusammensetzung von historischen und neuen Eisenerzproben aus dem Osterz- und Elbtalschiefergebirge untersucht. Ferner wird den Fragestellungen nachgegangen, wann diese Eisenerzlagerstätten erschlossen wurden, über welchen Zeitraum sie unter Abbau standen und wie viel Eisenerz aus den jeweiligen Gruben gefördert wurde. Hierfür erfolgte eine detaillierte Dokumentation der wichtigsten ehemaligen Eisenerzlagerstätten mit den dazugehörigen Zeugnissen des historischen Eisenerzbergbaus. Darauf aufbauend werden die Bedeutung des Eisenerzbergbaus und des daran angeschlossenen Eisenhüttenwesens für die wirtschaftliche und kulturelle Entwicklung des Gebietes untersucht. Des Weiteren werden die regionalen Beziehungen zu anderen Bergbau- und Wirtschaftszweigen aufgezeigt. Der Prozess des Aufbrechens der regionalen Wirtschaftsstrukturen im Zuge der Industrialisierung wird eingehend erläutert. Und die Gründe für den Niedergang des Eisenerzbergbaus und Eisenhüttenwesens werden ebenfalls genannt. Danach erfolgt eine Betrachtung darüber, welche bergbauhistorischen Zeugnisse heute im Gelände noch auffindbar bzw. welche Nachfolgenutzungen an den Standorten des historischen Eisenerzbergbaus und des Eisenhüttenwesens gegenwärtig vorhanden sind. Abschließend wird erläutert welche Schlussfolgerungen für die Nutzung des geotouristischen Potenzials sich daraus ergeben.
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33

Pflug, Norbert. "Der historische Eisenerzbergbau im Osterzgebirge und Elbtalschiefergebirge – eine geographisch-geologische Landschaftsanalyse." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-131472.

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Анотація:
Im Osterzgebirge sowie im nordöstlich daran angrenzenden Elbtalschiefergebirge wurde mit Unterbrechungen über mehrere Jahrhunderte Bergbau auf Eisen betrieben. Für die Besiedlung, den Bergbau auf andere Metalle, die Landwirtschaft und das Handwerk in der Region hatte der Eisenerzbergbau eine gewisse Bedeutung. Im Gegensatz zum Silber- und Buntmetallbergbau ist über den Eisenerzbergbau allerdings nur relativ wenig bekannt. Das Ziel dieser Diplomarbeit bestand deshalb darin, eine zusammenfassende geologisch-geographische Darstellung, die sowohl den historischen Eisenerzbergbau im Osterzgebirge als auch den historischen Eisenerzbergbau im Elbtalschiefergebirge beinhaltet, zu erarbeiten. Um ein hohes Maß an Vollständigkeit zu gewährleisten, wurden die Erkenntnisse aus Archiven, Bibliotheken und Sammlungen zusammengetragen. Überdies wurde auch auf das Fachwissen von Heimatvereinen, Bergbaumuseen und Hobbyhistorikern zurückgegriffen. Ferner wird im Rahmen dieser Arbeit untersucht, welche Typen von Eisenerzlagerstätten es im Osterzgebirge und im Elbtalschiefergebirge gab, wie diese entstanden sind, um welche Mineralisation und um welche Art von Eisenerztypen es sich dabei handelt. Mit den gegenwärtig zur Verfügung stehenden Methoden der Analytik (REM-EDX) werden zudem die Mineralparagenese und die chemische Zusammensetzung von historischen und neuen Eisenerzproben aus dem Osterz- und Elbtalschiefergebirge untersucht. Ferner wird den Fragestellungen nachgegangen, wann diese Eisenerzlagerstätten erschlossen wurden, über welchen Zeitraum sie unter Abbau standen und wie viel Eisenerz aus den jeweiligen Gruben gefördert wurde. Hierfür erfolgte eine detaillierte Dokumentation der wichtigsten ehemaligen Eisenerzlagerstätten mit den dazugehörigen Zeugnissen des historischen Eisenerzbergbaus. Darauf aufbauend werden die Bedeutung des Eisenerzbergbaus und des daran angeschlossenen Eisenhüttenwesens für die wirtschaftliche und kulturelle Entwicklung des Gebietes untersucht. Des Weiteren werden die regionalen Beziehungen zu anderen Bergbau- und Wirtschaftszweigen aufgezeigt. Der Prozess des Aufbrechens der regionalen Wirtschaftsstrukturen im Zuge der Industrialisierung wird eingehend erläutert. Und die Gründe für den Niedergang des Eisenerzbergbaus und Eisenhüttenwesens werden ebenfalls genannt. Danach erfolgt eine Betrachtung darüber, welche bergbauhistorischen Zeugnisse heute im Gelände noch auffindbar bzw. welche Nachfolgenutzungen an den Standorten des historischen Eisenerzbergbaus und des Eisenhüttenwesens gegenwärtig vorhanden sind. Abschließend wird erläutert welche Schlussfolgerungen für die Nutzung des geotouristischen Potenzials sich daraus ergeben.
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34

Green, Heather F. "Casting no shadow : overlapping soilscapes of European-Indigenous interaction in northern Sweden." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/13133.

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The Sámi’s past activities have been documented historically from a European perspective, and more recently from an anthropological viewpoint, giving a generalised observation of the Sámi, during the study period of AD200-AD1800, as semi-nomadic hunter gatherers, with several theories suggesting that interaction with Europeans, through trade, led to the adoption of European activities by certain groups of the Sámi (Eiermann, 1923; Paine, 1957; Manker and Vorren, 1962; Bratrein, 1981; Mathiesen et al, 1981; Meriot, 1984). However, there is almost no information on the impact the Sámi had on the landscape, either before or after any adoption of European activities, and none investigating what cultural footprint or indicators would remain from Sámi or European occupation and/or activity within the typically podzolic soils of Northern Sweden. Consequently the thesis aims to contribute to the gap in knowledge through the formation of a podzol model identifying the links between anthropogenic activity and the alteration of podzol soils, and through the creation of soils based models which identify the cultural indicators associated with both Sámi and European activity; formed from the identification of cultural indicators retained within known Sámi and European sites. The methods used to obtain the information needed to achieve this were the pH and magnetic susceptibility from bulk soil samples and micromorphological and chemical analysis of thin section slides through the use of standard microscopy and X-ray fluorescence from a scanning electron microscope. The analysis revealed that the Sámi had an extremely low impact on the landscape, leaving hard to detect cultural indicators related to reindeer herding in the form of reindeer faecal material with corresponding phosphorous peaks in the thin section slides. The European footprint however, was markedly different and very visible even within the acidic soil environment. The European indicators were cultivation based and included phosphorous and aluminium peaks as well as a deepened, highly homogenised plaggen style anthropogenic topsoil rich in ‘added’ materials. An abandoned European site which visibly and chemically shows the formation of a secondary albic horizon within the anthropogenic topsoil also provides an insight into the delicate balance of cultivated soil in northern Sweden, whilst reinforcing the outputs identified in the podzol model. Due to the almost invisible Sámi footprint on the landscape, areas of overlap were impossible to identify however, there was no evidence of the adoption of European cultivation activities at any of the Sámi sites investigated. The only known area of interaction between the two cultures was an official market place which had been a Sámi winter settlement prior to its use as a market site. This site showed none of the reindeer based Sámi indicators or the cultivation based European indicators, but did contain pottery fragments which could be linked to trade or occupation. Overall, the thesis reinforces the low impact expected of the semi-nomadic Sámi and sheds light on the underlying podzolic processes influencing the anthropogenically modified soils of Northern Sweden. The podzol model is reinforced by several findings throughout the thesis and the soils based cultural indicator models for both Sámi and European activity have been successfully tested against independent entomological and palynological data and therefore provide reliable reference material for future studies.
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35

Lin, Chih-Fang, and 林志芳. "An Action Research of Integrating Chinese Magnetism Technology History into the Teaching of Elementary School Science Curriculum." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99772169689739241621.

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Анотація:
碩士
國立臺中教育大學
科學應用與推廣學系科學教育碩士班
96
This study adopted the action research method to investigate how to integrate Chinese magnetism technology history into the teaching of elementary school science curriculum and further review the problems encountered, solving strategies, and professional growth of the researcher. The researcher first collected historical materials related to the Chinese magnetism and referred to the current concepts for the design of Science and Life Technology Curriculum to develop a teaching activity based on 「exploration of the myth of compass". The research subjects were 31 fifth-year students regularly distributed to a class and 2 groups of students (5 students in each group) in a mid-scale suburban elementary school in Changhua County. The 3.5-month experimental teaching was provided in the first and second semesters since Oct 2006. During the research process, data were collected from observation, interview, video-recording, and audio-recording, and further analyzed to modify, examine, and improve the designed teaching activity. Through the implementation, modification, and discussion of the teaching activity, the following results were obtained: 1. In the aspect of teaching design: The teaching design of technology history should be related to student’s interests and life experiences, and the content can be implemented and applied. According to student’s competence, the historical content can be modified into supplementary materials acceptable to students. 2. In the aspect of teaching implementation: When integrating technology history into teaching, it is necessary to adopt diverse teaching methods, so as to let students adequately engage into the exploration activities and increase their autonomous learning ability. Most of the students responded that they liked the teaching and felt they could acquire the knowledge about magnet and compassion and be benefited in the experiment. 3. In the aspect of teacher’s professional growth: The entire implementation process and presentation of the report were the source of the researcher’s growth. The researcher has gained improvement in the following aspects: knowledge about magnetism technology history, ability to compile computer programs, practical ability to teach technology history, and personal research ability. Finally, based on the research conclusions, some suggestions were proposed as a reference for practical applications and follow-up studies.
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36

Ferrer, Marta. "Alternative Presence: the Cultural Meaning of Heterodox Sciences in Nineteenth-Century Spain." Thesis, 2021. https://doi.org/10.7916/d8-03ka-ga18.

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This dissertation examines the cultural role of three controversial yet popular heterodox sciences of nineteenth century Spain: phrenology; animal magnetism and hypnosis; and spiritualism or spiritism. It assesses the relationship between the development of phrenology and early Catalanism, the connection of animal magnetism and hypnosis to both Catholicism and emergent medical discourse, and the flourishing of spiritism in the context of the production of a national genealogy. The project draws on myriad sources like literary works, daily newspapers, specialized journals, dissemination pamphlets, and case histories, to argue that these heterodox sciences were an integral part of the social and cultural history of the nineteenth century. It rethinks not just the relationship between science and cultural production that scholars like James Secord, Gillian Beer, and others have studied but also what we understand as nineteenth-century scientific heterodoxies, seeking to understand them as a broad socio-cultural phenomenon in the way they helped construct cultural practices of the time. Alternative Presence contends that phrenology, animal magnetism and hypnosis, and spiritism expanded rhizomatically away from the confines of canonical institutions and yet contributed to early political regionalism, practices of medical and religious healing, and national historiography. To study such mediations, I look both at these sciences’ main actors — heterogeneous individuals and groups who disseminated them — and at a series of narrative and expressive strategies visible in the discourse through which they flourished. As the term “science” evolved and gained social authority through the appearance of increasingly demarcated fields of expertise, heterodox sciences’ tessellated networks lost ground and were ultimately relegated to the sphere of pseudoscience or popular belief. However, during their lifetime they served to generate alternative ideas of the subject and the nation. Their crucial role in the nineteenth-century Spanish cultural field has been ripe for rediscovery, and this dissertation probes their imbrication with mainstream ways of imagining the paths to modernity.
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37

Audunsson, Haraldur. "Paleomagnetism, magnetic properties and thermal history of a thick transitional-polarity lava." Thesis, 1989. http://hdl.handle.net/1957/29359.

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Анотація:
The Roza flow of the Columbia River Basalt group in Washington State U.S.A. extruded at about 15 Ma during intermediate geomagnetic polarity. The Roza is underlain by normal polarity flows and overlain by reversed units. The Roza is an extensive flow, up to 60 in thick. As the remanence-blocking isotherms progressed into the flow, it recorded a short continuous segment of the transitional geomagnetic field. Our studies show limited thermal remagnetization in the underlying flow, and we infer that groundwater was effective in extracting the heat. The extent of basement heating was further reduced by the insulating scoria immediately beneath Roza. Hence, the Roza flow cooled symmetrically from its top and base. Samples from the drilicores acquired drilling induced remanent magnetization (DIRM), shown to be well modelled as an isothermal remanent magnetization produced in nonuniform fields of the order of 10 mT at the rim of the drillstring. Alternating field demagnetization was usually successful in removing the DIRM. The remanence stability is higher in the top third of Roza, due to smaller magnetic particles, than in the lower two thirds of the flow, where the magnetic properties are nearly uniform. The stability profile corresponds to the entablature/colonnade subdivision. High temperature subsolidus oxidation of the titanomagnetites increased with height in the flow, altering the primary symmetric intraflow distribution. The declination of the Roza flow sampled at numerous outcrops is consistently about 189°. In a 54 m drillcore section, Roza inclinations become more negative towards the flow interior, consistent with its magnetostratigraphic position. Superimposed is a symmetric, rapid change in inclination from -2 to -15° and back to -5°. The flow's thermal history predicts that these fluctuations have a characteristic time between 15 and 60 years, such that the inclination changed at a rate of 1/2 to 2° per year, showing that the directions of this transitional field fluctuated several times more rapidly than the present geomagnetic field. However, considering the generally reduced intensity during transitions, these fluctuations might not be unusual.
Graduation date: 1990
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38

Maré, Leonie Pauline. "Geothermal history of the Karoo Basin in South Africa inferred from magnetic studies." Thesis, 2015. http://hdl.handle.net/10210/13879.

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Анотація:
Ph.D (Geology)
The Karoo succession has economic significance through the exploitation of extensive coal deposits and in recent years has seen significant international interest due to potentially large shale gas resources. The thermal history of sedimentary basins affects the genesis of hydrocarbon deposits and it is therefore essential to model and reconstruct the geothermal variation across the Karoo Basin before evaluation of the hydrocarbon resources can take place. The main scientific questions related to the thermal history of the Karoo Basin are whether the emplacement of large volumes of magma was preceded by a large-scale lowgrade thermal doming as proposed for continental rift settings. Alternatively, was the Karoo thermal event restricted to the contact aureole of intrusives, as well as the question whether the intrusion of dolerite resulted in large-scale CO2 or CH4 degassing from coalbeds and carbonaceous shales based on similarities to other large igneous provinces? Magnetic techniques provide an alternative to more traditional methods to study the geothermal history of sedimentary basins (such as illite crystallinity and vitrinite reflectance), which are often associated with significant uncertainty. Three experiments using existing magnetic and palaeomagnetic methods were conducted to determine the peak temperatures reached by Karoo sedimentary rocks before and after the Karoo magmatic event. These experiments include the classic palaeomagnetic baked contact tests (magnetostratigraphy), analyses of the variation of magnetic susceptibility during repeated progressive heating (alteration index method) as well the variation of relative concentrations of fine grained pyrrhotite and magnetite in sedimentary strata relative to their distance from an intrusive (pyrrhotite/magnetite geothermometer). Additionally various magnetic fabric analyses were performed including a study of the variation in anisotropy of magnetic susceptibility (AMS). Although these techniques were successful in delineating the extent of the contact aureoles, only the alternating index (A40) had the ability to give estimated peak temperatures. Results indicate a general elevation of palaeotemperatures of the organic-rich sedimentary rocks of the Ecca Group to temperatures where hydrocarbons are normally converted into gas. Importantly, it is clear from this study that the greatest thermal effects of the sill intrusions on the sedimentary strata are limited to the contact aureoles, suggesting that there is an, as yet unquantified, potential for hydrocarbon resources remaining between these intrusions. A general increase in the palaeotemperatures from southwest to northeast across the basin was observed. This is mainly due to differences in thermal conductivity of the various lithologies across the basin from tight low porosity marine shales in the south and southwest towards more lacustrine mudstone and porous sandstone in the northeast.
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39

Barrulas, Raquel Alexandra Valadares. "Treatment of paper biodeterioration by fungi: An NMR approach to the preservation of human history." Master's thesis, 2019. http://hdl.handle.net/10362/63791.

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Анотація:
The main goal of this dissertation was to develop a new class of materials in order to provide an improved solution to clean fungal staining in paper. Initially a screening of favourable interactions between pigment model compounds and ionic liquids (ILs) was accessed through Nuclear Magnetic Resonance (NMR) protocol. The most promising IL moieties were incorporated into polymer matrices. The final products were tested against contaminated paper samples. The NMR approach allowed profiling the molecular interactions prevailing between ILs with cations such as 1-butyl-3-methylimidazolium ([BMIM]+), 1-ethyl-3-methylimidazolium ([EMIM]+), 1-butyl-2,3-dimethylimidazolium ([BDMIM]+), 1-benzyl-3-methylimidazolium ([BZMIM]+); and anions such as chloride, trifluoromethanesulfonate ([OTf]-), dicyanamide ([DCA]-) and tricyanomethanide (TCN]-), and model compounds (naphthalene, L-DOPA, veratrole, alizarin and quinizarin) with identification of the structural features in the IL pair responsible for the preferential interactions. The ILs [EMIM][TCN], [EMIM][OTf] and [EMIM][DCA] exhibited better interaction abilities with stronger interactions – hydrophobic and π-π stacking interactions. The monomers with cations [ETVIM]+ and [BVIM]+ as well as with anions [DCA]-, [OTf]-, bromide and [NTf2]- were synthetized and polymerized afterwards, with very high yields. Hydrogels derived from polymeric ILs (PILs) and agarose and/or PVP were obtained. The efficacy of the hydrogels obtained was tested on contaminated paper samples with A. niger, C. cladosporioides, P. chrysogenum and F. oxysporum. The most promising results were obtained with hydrogels with poly([ETVIM][DCA]) and poly([BVIM][OTf]) against P. chrysogenum and A. niger, respectively.
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40

Gayler, Lucyna Maria. "A palaeoenvironmental history of the Paroo and Warrego Regions, Australia: a multi-proxy, multi-site approach." Thesis, 2008. http://hdl.handle.net/1959.13/33470.

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Анотація:
Research Doctorate - Doctor of Philosophy (PhD)
The records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.
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41

Gayler, Lucyna Maria. "A palaeoenvironmental history of the Paroo and Warrego Regions, Australia: a multi-proxy, multi-site approach." 2008. http://hdl.handle.net/1959.13/33470.

Повний текст джерела
Анотація:
Research Doctorate - Doctor of Philosophy (PhD)
The records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.
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42

Fushai, Felix. "Fermentability of dietary fibre and metabolic impacts of including high levels of fibrous feed ingedients in maize-soyabean growing pig diets supplemented with exogenous enzymes." Thesis, 2014. http://hdl.handle.net/10500/14220.

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Анотація:
The objectives of the research were to examine the effects of high dietary levels of fibrous feeds, and of supplementation with Roxazyme® G2 (RX), on the digestive metabolic and physiological responses of growing pigs fed maize-soybean diets. The nutrient and dietary fibre (DF) composition, the swelling and water-binding capacities of maize (MM), its hominy chop (HC) and cobs (MC), dehulled soybean (dSBM) and the hulls (SH), brewer’s grains (BG), lucerne hay (LH) and wheat bran (WB) were evaluated using standard procedures. Feed fibre fractions were isolated by simulating upper tract digestion in an Ankom® DaisyII Incubator, whereby each feed was digested in pepsin (porcine, 200 FIP-U/g, Merck No, 7190), followed by pancreatin (porcine, grade IV, Sigma No P-1750), with recovery of the fibrous residues. In a third step to complete the simulated pig gastro-intestinal digestion, the pepsin-pancreatin fibre extracts were digested by RX or Viscozyme L ® V2010 (VZ). Enzyme activity was measured as the coefficients of partial degradability (solubilisation) of the washed fibre extracts. The kinetics and products of fermentation of the DF were evaluated in an AnkomRF gas production system, using buffered faecal inoculum. Among the feed ingredients, dissimilar, fibre source-dependent activities between RX (0.02 to 0.12) and VZ (0.04-0.33) were observed. The lowest RX activities were observed on the maize and soybean derived fibres, with similarly low VZ activity on MC fibre. Variation in the activity of faecal microbial enzymes was similarly indicated by the variable production of fermentation gas (51.8-299.4 mL g-1 DM) and short chain fatty acids (SCFA) (2.3-6.0 mMol g-1 DM). Soy hull, dSBH, MM and HC fibres were highly fermentable, with low fermentability of BG, MC and WB fibres. The fibres differed in the composition of fermentation SCFA, whereby SH, LH and MC shifted fermentation to Ace, and BG, dSBM, WB, MM, HC favoured Pro, while MM and HC favoured But production. The same nutritional properties were similarly evaluated in complete diets which were formulated from the ingredients for growth, and metabolic trials. For the growth trial, a standard (STD) (control), 141 g total dietary fibre (TDF) kg-1 dry matter (DM) maize-soybean growing pig diet, and five iso-nutritive, 246 g TDF kg-1 DM nutritionally balanced diets were formulated. The high DF was achieved by partial replacement of the MM and dSBM in the STD diet with MC, SH, BG, LH or WB. The differences in RX and VZ activities and in the fermentation characteristics which were observed on the fibre extracts from the high fibre ingredients were reflected in the DF from the respective complete diets in which they were included. However, the fibre from the basal dietary ingredients reduced the absolute values and the variation in the activities of RX (0.03-0.06) and VZ (0.16-0.22), and similarly reduced the variation in gas (126.6-187.6 mL g-1 DM) and SCFA (4.1-5.4 mMol g-1 DM) production of the DF from the fibrous diets. Enzyme activities on the STD DF were low for RX (0.03) and high for VZ (0.25). The STD DF produced 205.3 mL gas g-1 DM, which was similar to SH DF, and higher than all the other diets. The STD DF produced 5.0-mMol SCFA g-1 DM, which was quantitatively, and not statistically higher than the other fibres. The composition of SCFA was similar across all diets, except for the high percent Ace, with low Pro by the SH DF. Compared to the STD, the high DF diets increased percent Ace, with reduced Pro and But. The STD, MC, SH, BG, LH and WB diets were each prepared in duplicate mixes, one of which was fortified with 200 mg RX kg-1 feed (as fed). Seventy-two intact Large White X Landrace, male, 32.0 ± 5.6 kg live weight (LW) pigs were allocated to the diets in two completely randomised weight blocks in a 2 (fibre source) X 2 (enzyme) factorial arrangement. The pigs were fed ad libitum for 10 weeks. Cumulative LW gain and feed intake were measured at different stages of growth, and at slaughter. Apparent total tract digestibility (ATTD) of nutrients was estimated at 65-70 kg LW, using 0.2% (as fed) chromium oxide as the indigestible marker. Ileal tissue was sampled 50 cm above the ileo-caecal valve, on which villi height and area, and crypt depth were evaluated by computerised image analysis. Blood was sampled at slaughter from the severed vena jugularis, 16 hours after feeding. Serum urea, creatinine, triglycerides, glucose, and total cholesterol were analysed chemically. The serum metabolome was further explored using Proton Nuclear Magnetic Resonance Spectroscopy (1H -NMRS). There was fibre X RX interaction for villi height, whereby the enzyme reduced the villi height in pigs on the SH, STD and WB diets, with an opposite effect on pigs on the MC, BG, LH diets. The soluble fibre content was negatively correlated with crypt depth. Chemical analysis did not detect differences in metabolite concentration between the STD and the high fibre diets. However, more serum cholesterol was observed in pigs fed the WB compared to the LH and MC diets. 1H-NMRS indicated that feeding pigs the WB diet increased serum Cys and His, while supplementation of RX increased serum formate, glucose, and urea. There was diet X enzyme interaction for fructose, glucose, Arg, Cys, Ser, and Trp, whereby RX increased the levels in pigs on MC and WB, with an opposite effect in pigs on the other diets. There was large DF source-dependent variation among diets in ATTD of DM (0.80-0.85), organic matter (OM) (0.81-0.87), gross energy (GE) (079-0.85) and CP (0.81-0.85), whereby, relative to the STD diet, high DF reduced the ATTD of DM (all diets except SH), organic matter (OM) and energy and CP (all diets except the MC). Positive correlation was observed between fermentability and the ATTD digestibility of DM, OM, energy, ADF, NDF, and fat. Negative correlation was observed between the swelling capacity and the ATTD of DM, OM, energy and protein, between DF solubility and DM, OM, protein, ADF and NDF, and between water binding capacity and ATTD of DM and OM, energy and NDF. At slaughter, there was similarly large, and DF source-dependent variation among the high fibre diets in feed intake (2.31-2.71 kg as fed day-1), live weight gain (0.75-0.86 kg day-1), and feed: gain ratio (2.73-3.00). Corresponding values for the STD diet were 2.44 kg day-1, 0.83 kg day-1and 2.86 kg day-1, respectively. Relative to the STD, LH reduced feed intake and live weight gain, and MC increased the feed: gain ratio. Predictions based on the in vitro fermentability of DF and feed intake suggested that due to poor fermentability, and or restriction of feed intake, relative to a standard fibre diet, high dietary levels of MC, WB and BG may reduce fermentation in the lower gut, while similar dietary levels of SH and LH may result in substantial increases in fermentation. At 50 kg LW, the fermentability of DF was positively correlated with feed intake and with weight gain, while water binding capacity and solubility of DF were negatively correlated with feed intake. At slaughter, the solubility of DF was negatively correlated with feed intake and feed: gain ratio. Large variation among the high fibre diets was also observed in the slaughter weight (89.2-96.8 kg), dressing % (68.6-76.4), meat colour (80.4-82.3), lean % (69.5-71.2), and fat % (10.1-12.6). In comparison, pigs on the STD diet scored 94.7 kg slaughter weight, 75.1% dressing, 81.6 cm carcass length, 82.5 meat colour, 68.4% lean, and 15.0% fat. Relative to the STD, LH reduced dressing and fat %. Lucerne hay and WB increased the lean%. For the metabolic trial, two iso-nutritive, mixed high fibre (319 g TDF kg-1 DM), nutritionally balanced diets were formulated to contain DF of high (HF) versus low (LF) fermentability. The diets had similar content of soluble DF and similar swelling and water binding capacities. Viscozyme was more active than RX on both the HF (0.20 versus 0.04) and the LF (0.17 versus 0.07) DF. The combination of RX and VZ statistically increased the enzyme activity on the HF (0.25) and quantitatively increased enzyme activity on the LF (0.18) DF, suggesting additive or synergistic effects. More gas was produced by the HF (159.5 mL g-1 DM) compared to the LF DF (96.6 mL g-1 DM). More SCFA were produced by HF (5.0 mMol g-1 DM), compared to the LF DF (3.6 mMol g-1 DM). Compared to the STD, HF DF increased percent Ace, with reduced Pro and But. The LF DF increased percent Ace, with quantitative, and not statistical reduction of Pro and But. In a metabolic trial, the HF and LF diets, and their duplicates containing 0.270 g RX kg-1 DM of feed (as fed) were fed ad libitum to eight ileum T-cannulised, intact Large White X Landrace male pigs weighing 65.0 ± 5.1 kg. The diets were allocated to the pigs in a duplicate 4 x 4 Latin Square design, in a 2 (enzyme) x 2 (fermentability) factorial arrangement. Each period consisted of two weeks of adaptation followed by five days of sampling. The ileal digesta was collected in each period and was similarly subjected to the fermentation test. Apparent ileal digestibility (AID) and ATTD were determined using 0.2% (as fed) chromium oxide as the indigestible marker. N excretion in faeces and urine were measured, and N retention was calculated. Blood was sampled by vena jugularis puncture on the last day of each period. Two blood samples were collected, the first 15 hours after removal from feed (15-hour serum), and the second 3 hours after re-introduction to feed (3-hour serum). Serum metabolites were evaluated by both chemical analyses and by 1H-NMRS, as described for the growth trial. Roxazyme did not affect the fermentation characteristics of the ileal digesta. In similar proportion to the fermentability of the PP digesta, the HF ileal digesta was more fermentable (65.4 mL gas g-1 DM and 6.1 mMol SCFA g-1 DM) than the LF ileal digesta (46.7 mL gas g-1 DM and 4.4 mMol SCFA g-1 DM SCFA). Prediction based on the in vitro fermentability of DF and feed intake suggested the HF diet could support one half times more fermentation in the lower gut compared to the LF diet. The HF diet had higher AID of DM (62.5 vs. 58.6), OM (65.6 vs. 62.1), energy (64.4 vs. 61.0), fat (85.8 vs. 81.7) and ash (41.8 vs. 32.7). The AID of HO-Pro, Met and Val were higher for the LF diet. There was diet X enzyme interaction on the AID of Met, whereby the RX reduced the AID of met in the LF diet, and not that of the HF diet. The ATTD was higher for the HF diet for DM (74.2 vs. 68.4), NDF (64.7 vs. 57.4), and ADF (35.1 vs. 21.0). There was positive correlation between the fermentability of DF and the AID DM, OM, ash, ash, fat and energy. The solubility of DF was negatively correlated with the AID of DM, OM, ash, fat, ADF and energy, and with the ATTD of DM, OM, ash, fat, energy, NDF, and ADF. Negative correlation was also observed between the swelling capacity of DF and the AID of protein, Trp and Lys. The solubility of DF was positively correlated with Ser, Ala, Val, Iso-Leu and His. There was diet X enzyme interaction for urea in the 15- hour serum, whereby RX tended to reduce the urea in the LF diet, while it increased that of the HF diet. Fermentability negatively correlated with urea in the 15- hour serum, and positively correlated with serum glucose in the 3-hour serum. In the 3-hour sample, 1H-NMRS indicated higher fucose, Pro and cholesterol in the LF diet. 1H-NMRS also indicated fermentability x RX interaction for Ser, Tyr, Lys, creatine, and possibly, glucose or fructose, glycerol or Gly and His or Arg, whereby RX increased the levels in the LF diets, with opposite effect in the HF diet. In conclusion, enzyme activities and fermentability were higly variable among different DF sources, and the effects were evident in the fibrous complete diets. The results of the in vitro studies supported the application of the methods to formulate fermentable insoluble fibre-rich, maize-soybean-mixed co-product diets. Correlation analyses suggested that DF fermentability, and solubility, swelling and water binding capacities explained significant proportions of the variances of the metabolic and physiological responses of the pigs to different feeds. Predictions based on the in vitro fermentability of DF and feed intake suggested that a strategy whereby pig diets are enriched in DF after the feedstuffs are screened on DF fermentability could substantially increase fermentation in the lower gut. Overall, the results suggested that productivity can be maintained in growing pigs fed diets containing up to twice the standard levels of DF, provided producers target co-product feeds that contain highly fermentable DF. The use of RX to improve nutrient digestion and to stimulate gut fermentation was not justified.
Environmental Sciences
Ph.D. (Environmental Sciences)
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